1. Field of the Invention
The present invention relates to oral tobacco, and particularly to raw material chips used for oral tobacco referred to as SNUS, and a method for manufacturing the raw material chips for the oral tobacco.
2. Description of the Related Art
Conventionally, as oral tobacco, which is smokeless tobacco, Snuff which is used by directly placing tobacco particles in the oral cavity to relish flavor has been known. But, in recent years, as oral tobacco in which the ease of handling for a user is improved, products referred to as SNUS have been widely known. In SNUS, a composition including tobacco particles, water, and the like is used as an oral tobacco raw material, and a pouch in which the composition is placed in a packaging material made of a nonwoven fabric or the like as a material is used as one unit. A plurality of pouches placed in a container are sold as a SNUS product.
The oral tobacco raw material including the composition including tobacco particles, water, and the like (hereinafter also simply referred to as an oral tobacco raw material), constituting the unit of SNUS, contains a relatively high content of water, considering the usability of the product for a user. Thus, the flowability of the oral tobacco raw material worsens, and a drawback is that the oral tobacco raw material is difficult to handle in the manufacturing process of SNUS.
In order to solve this, as an attempt to focus on methods for manufacturing oral tobacco, technical studies have been made largely in two directions so far.
The first direction is the study of mechanisms for stably delivering an oral tobacco raw material including a high content of water (for example, see International Publication No. WO2008/062301, International Publication No. WO2008/062302, and International Publication No. WO2009/025604). These Patent Literatures mainly disclose mechanisms for dropping an oral tobacco raw material into a void (measure) having a fixed volume and having, for example, a cylindrical shape and the like, and then delivering the oral tobacco raw material by compressed air or a tamping bar, and methods for using the same. International Publication No. WO2008/114133 and International Publication No. WO2008/114128 disclose mechanisms for sucking and blowing off an oral tobacco raw material on a drum for conveying an oral tobacco raw material, and methods for flushing the periphery of the mechanism portions.
On the other hand, the second direction is a study for improving the properties of an oral tobacco raw material including a high content of water itself. International Publication No. WO1998/008738 and International Publication No. WO2008/103080 disclose mechanisms for pressing and delivering an oral tobacco raw material by a compression drum or a compression belt.
International Publication No. WO2006/065192 discloses a method for forming an oral tobacco raw material into a sheet shape and punching it by a die.
In addition, another problem is that due to the high water content in the above oral tobacco raw material constituting the unit of SNUS, the water in the above oral tobacco raw material seeps through the nonwoven fabric, and thus, the appearance of the pouch is impaired.
Regarding this, Japanese Patent Laid-Open No. 2010-525800 discloses a method for manufacturing a pouch, including the step of cooling a composition containing tobacco particles and water to 0° C. or less before placing it in a packaging material and sealing it.
The systems described in International Publication No. WO2008/062301, International Publication No. WO2008/062302, and International Publication No. WO2009/025604 can be used for an oral tobacco raw material substantially including about 20 to 30% by weight of moisture. But, when they are applied to one including about 50% by weight of moisture, problems arise that when it is dropped into the void in the pouch manufacturing apparatus into which an oral tobacco raw material is put, its amount is variable, and after being delivered, the oral tobacco raw material easily clogs the downstream path, such as the conveyance tube.
Compared with the above methods, the methods described in International Publication No. WO2008/114133 and International Publication No. WO2008/114128 can also be used for an oral tobacco raw material including a high content of water. But, in the pouch manufacturing apparatus, the clogging of the sucking portion where the oral tobacco raw material is sucked, or entry into the drum may occur, and the structure of the apparatus is complicated, and the cost including that of maintenance is high.
The methods described in International Publication No. WO1998/008738 and International Publication No. WO2008/103080 aim to obtain a formed piece including the oral tobacco raw material in an amount corresponding to one pouch, and the ease of handling of the oral tobacco raw material is improved, but the pouch including the oral tobacco composition obtained by the methods gives an uncomfortable feeling as a lump of the formed piece to a SNUS user. In addition, in the method described in International Publication No. WO1998/008738, it is necessary to include a mechanism for compressing the oral tobacco raw material, and a mechanism for discharging the oral tobacco raw material, in the drum, and therefore, the apparatus is complicated and expensive. In addition, the number of components also necessarily increases, and therefore, the ease of cleaning, that is, cleanliness, may decrease. In the method described in International Publication No. WO2008/103080, the severing size of the formed piece is determined by the shape of the belt for conveying oral tobacco, and therefore, another problem is that when the size of the formed piece is changed, the above belt, the pulley for moving the belt, and the like must be changed.
In the method described in International Publication No. WO2006/065192, a polysaccharide or the like is mixed in the oral tobacco raw material so that it hardens easily, and the oral tobacco raw material is punched into a thickness of about 5 mm and a diameter of about 12 mm, and then dried and fixed. Therefore, the product gives an uncomfortable feeling as a lump of the formed piece to a user, like the formed pieces described in International Publication No. WO1998/008738 and International Publication No. WO2008/103080.
In the method described in Japanese Patent Laid-Open No. 2010-525800, the step of cooling the oral tobacco raw material before sealing it in a packaging material is necessary, and therefore, further one step is necessary in the manufacturing of the pouch.
From these, there has been a need for an oral tobacco raw material that is easily handled during the manufacturing of oral tobacco, does not stain a packaging material when packaged as a pouch, and does not cause a feeling of a lump and rapidly emits flavor when a user uses the pouch by placing it in the oral cavity, and there has been a need for a method for manufacturing such an oral tobacco raw material, and a method for stably obtaining oral tobacco at low cost using the oral tobacco raw material.